Analysis of powered two-wheeler accident scenarios and multi-body simulations to support trunk protective equipment impact test methods.

Powered two-wheeler (PTW) riders are most frequently injured seriously to the thorax. Some thorax protective devices have been developed in order to reduce thorax injuries. Nevertheless, actual tests and standard lack real-world accident representativeness. The aim of the study was to determine realistic trunk impact conditions for accidents likely to result in thorax injury. The study is divided into two phases: a literature review to classify accident scenarios based on rider kinematics, and numerical simulations to analyze the riders impact conditions. Three accident scenarios have been found through a literature review and their main configurations have been numerically investigated via multi-body modeling. The 912 performed simulations were used to explore body contacts with counterparts over time, relative velocities and relative body orientation at impact. The results have highlighted the necessity of a conservative activation time delay for triggering protective devices. They have also led to propose three realistic impact conditions that can be used in future test protocols.